"Fluent solid material" is used herein as a generic term to include pulverulent or granular material which is capable of flowing freely, either in an unassisted gravity system or in aerated or liquid slurry form.
Systems for handling fluent solid material must include means for moving the pulverulent material from one or more collecting hoppers into a transport device. Depending upon the nature of the material, it may be transported for use in its raw state, or for further processing, or for mixing with another material as filler, or for disposal as waste. The use to which the material gathered in the collecting hoppers is to be put determines the state in which it should be delivered to a transport device.
One very desirable way of handling fine, pulverulent material, such as the large quantities of fly ash produced by a high capacity coal-burning steam boiler, is to mix it with a predetermined quantity of liquid, usually water, to eliminate the enormous dust problem which accompanies the handling of such material. On the other hand, there may be some circumstances in which the collected pulverulent material must be transported in the dry state.
Patents known to applicant and his attorney which are most pertinent to the present system include U.S. Pat. Nos. 2,648,572; 3,653,639; 3,809,436; and 4,200,412.